Triisopropyl borate → (5-Bromo-4-methyl-pyrimidin-2-yl)-bis-(4-methoxy-benzyl)-amine

Participants

Reaction Steps

To a solution of (5-bromo-4-methyl-pyrimidin-2-yl)-bis-(4-methoxy-benzyl)-amine (1.28 g) obtained through the reaction of 5-bromo-4-methyl-pyrimidin-2-ylamine and 4-methoxybenzyl chloride in DMF in the presence of 60% oily sodium hydride, and boric acid triisopropyl (1.94 ml) in THF/toluene (4.2 ml/17 ml), at −78° C., n-butyl lithium-hexane solution (1.6 M, 4.5 ml) was added dropwise, followed by stirring at −78° C. for 1 hour. To the reaction mixture, water (10 ml) was added, and a colorless precipitate resulting from the addition of concentrated HCl (500 μl) was filtered, to obtain 2-{bis-(4-methoxy-benzyl)-amino}-4-methyl-pyrimidin-5-boronic acid. Then, the resulting colorless precipitate (787 mg), pinacol (248 mg) and magnesium sulfate (248 mg) were stirred in dichloromethane (10 ml) for 1 hour, followed by filtering off insolubles, and the filtrate was concentrated under reduced pressure, to obtain bis-(4-methoxy-benzyl)-[4-methyl-5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-pyrimidin-2-yl]-amine (275 mg, 29%) as a colorless amorphous.

Provenance & Evidence